I'd say wait until you're 75 for any endgame activities, and have both WHM and RDM leveled to 37 first.
Yes endgame is like a frat of players you spend a lot of time with, but in an 18 man alliance to fight in sky, a KSBC99, or even in dynamis, every spot counts and every member counts. Dedication to any end-game LS is just as important as the victory and the rewards you receive from it. You can't get effective victories without maximizing your character's potential. Also if your nukes are resisted, you're just taking a spot that someone else could use to provide an effective victory with minimal casualties.
Don't be in a rush to get into an end-game LS because you lose a lot of your time due to the schedules the leaders place before you. Many times you sacrifice your personal goals for the greater good of your LS. Countless times we've all lost experience points, ate Raise 1's, just so we can get back in swinging again to get a the short-sighted victory. Then you come back the next day, die a couple more times, and realize you've come close to deleveling.
It takes a different mind-set to play that way, and until you're ready, don't do it. There will always be some LS recruiting players like yourself . . . just make sure you know what you're getting into.
The rewards are sweet, the friends you meet along the way are nothing short of spectacular, but again, it's a whole different type of playing than your casual experience points party from 1-75.